Method and apparatus for applying a fibrous coating to a filament



Sept. 27, 1938. c. F. oB-ERMAIER 2,131,598

METHOD AND APPARATUS FOR APPLYING A FIBROUS COATING TO A FILAMENT Filed sept. 28, 1954 HIIIHHHII Il Patented Sept. 27, 19384 UNIT- ED STATES METHOD AND APPARATUS FOR APPLYING A FIBROUS COATING TO A FILAMENT Carl `F. Obermaier, York, Pa., assignor to General Electric Company, a corporation of New York Application September 28, 1934, Serial No. 745,871

16 Claims.

My invention relates to method and apparatus for applying fibrous material to a filament, more particularly for applying fibrous insulation material, such as asbestos fibres, to an electrical 5 conductor and the like, and it has for its object the provision of improvedv method and apparatus for applying brous material to a conductor in a simple, reliable, economic and eflic,

20 contact with the conductor except at one end of the mass Where the fibres contact the conductor. A fresh supply of fibres is continuously delivered to the rotating mass of fibres and advanced longitudinally of the mass toward the end thereof Where they contact the conductor and become attached to it. If desired, an adhesive may be applied to the surface of the conductor before it reaches the zone of application of the fibres so that the fibres are caused firmly to adhere to the conductor by said adhesive coating.

The cylindrical mass of fibres may be conveniently formed by delivering the fibres directly to a rotary cylindrical conveyor which'surrounds the conductor and rotates on it as an axis. The

I fibres are fed to the cylindrical conveyor in a formless mass, preferably throughout the length ofthe conveyor. This may be accomplished conveniently by feeding the fibres directly to the conveyor from any suitable well-knowncarding machine, the fibres being acted upon by a suitable comb or equivalent device to destroy their parallelism before they are applied to the conveyor.

The rotary conveyor is arranged to feed the mass of fibres forwardly to one of its ends where the fibres are applied to the conductor and becomev attached to it by theadhesive on it, and at the same time imparts to the mass of fibres a rotary motion about the conductor. The mass of fibres, therefore, is given two motions, one forwardly with the conductor in its direction of travel, and another in a rotary direction about the conductor. These two motions arrange the fibres on the surfacev of the conductor in nonparallel, and interlentangled twistedrelation,

Auxiliary means are provided to assist the conveyor to move the fibres to the zone of application on the conductor and to impart to the fibrous mass its rotary motion.

'Ihe fibres in the application zone on the con- 5 ductor are further twisted about and condensed upon the conductor by means of a suitable whirler.

This application is a continuation in part of my copending application, Serial No. r102,155, filed 10 December 13, 1933 and assigned to the same assignee as this invention.

For a more complete understanding of this invention, reference should be-had to the accompanying drawing in which Fig. 1l is a diagram- 15 matic elevation of apparatus for applying fibrous material to a filamentary body arranged in accordance with this invention; Fig. 2 is an end elevation of a portion of the apparatus shown in Fig. 1, taken on an. enlarged scale; Fig. 3 is a 20 front elevation of the apparatus shown in Fig. 2; Fig. 4 is an enlarged elevation mainly in section of a portion of the apparatus shown in Figs. 1, 2 and 3; Fig. 5 is an enlarged elevation in section ofa portion of the apparatus shown in Fig. 1; 25 Fig. 6 is an enlarged elevation of 4a portion of the apparatus shown in Fig. l; and Fig. 7 is a front view of the apparatus shown in Fig. 6; and Figs. 8 and 9 are views in elevation illustrating various other forms of conveyors for receiving 30 and delivering the fibrous material to the filamentary body, both arranged in accordance with this invention.

Referring more particularly to Figs. 1-3 inclusive, I have shown my invention in connection 35 with means for applying asbestos fibres to anelectrical conductor. As shown, the filament or conductor I0 is advanced in a longitudinal direction from a suitable supply spool II to a suitable collecting spool I2. It will be understood that 40 any suitable means may be provided for advancing the conductor between the two spools. Thus, for example, a suitable motor or other suitable driving means may be attached to the spool I2 for revolving it so as to draw the conductor 45 lthrough the apparatus from the spool II to the idler guiding rolls I3 and I4 whereby the conductor is caused toadvance in a predetermined direction between the spools II and- I2. The member I4 may also be used to draw the conductor III through the apparatus whether the 55 member I2 or the member I4 is used for this purpose, it should have a variable speed control.

Asbestos fibres which are to be applied to the conductor I0 are treated by means of any suitable well-known carding machine so as to produce a line fleece of iiocculent material, the iibres being combed, separated, and arranged in substantially parallel relation with respect to each other. This carding apparatus is provided with a `carding drum I5 and with' various worker and fancy rolls (not shown) associated therewith and which cooperate With the drum to act upon the fibres so as to separate them and to arrange them in substantially parallel relation. It will be understood that raw asbestos fibres fed into the carding apparatus will be worked by the worker and fancy rolls so as to be cleaned, combed, and separated and arranged in substantially parallel relationship with each other. The fibres thus treated are stripped from the carding drum I5 by means of a dofier cylinder or ring I6, and from the doffer ring by means of a vibratory comb I'I. The drum I5 and the ring I6 rotate in the directions indicated by the arrows associated with these members in the drawing. It is believed to be unnecessary to describe in greater detail the carding apparatus including the 'carding drum I5, the doifer drum I6, and the vibratory comb I '1, because all of these elements are old and well-known to those skilled in the art.

Arranged directly opposite the dofler drum I6 is a rotatably mounted cylindrical conveyor I8. This conveyor, as shown, has a tubular form and is arranged so that the conductor I 0, as it advances between the guides I3 and I4, passes through the conveyor I8. Preferably, the conveyor I8 will be arranged so that its axis of rotation is substantially coincident with the conductor. As shown, the conveyor is provided with a suitable journal I9 at one end which is received in a bearing that is arranged to support the conveyor for rotation about the conductor III' as an axis. The conveyor I8 is provided with a pulley 2| over which any suitable driving belt 22 is passed to effect rotary motion of the conveyor. As shown, this belt 22 is directed over a pulley 23 which is arranged to rotate with the carding drum I5. It will be understood however that any other suitable source of power may be used to drive the conveyor I8. yIt is contemplated that the conveyor will be driven in a clockwise direction, as viewed in Fig. 2, and in the particular :form-of the invention shown it is driven at approximately 45 Rl. P. M.

The conveyor I8 as shown is mounted with relation to the doier drum I6 so that the libres which are stripped from the doffer by the vibratory comb I1 fall by gravity directly onto the rotary conveyor. The conveyor I8, as shown, has a length substantially equal to the width of the dolier drum I5. This is not necessary, however,

vand the conveyor may be considerably shorter than the Width of the drum.

As shown in Fig. 1, the conveyor I8 has a substantially conical formation, the outer surface of the conveyor tapering downwardly to its smaller diameter or apex in the direction of travel of the iilament I0.

The asbestos fibres are stripped from the doffer ring i6 by the comb il and drop down in a mass upon the surface of the conveyor I8 in such manner that all parallelism of the iibres is completely destroyed. This mass of indiscriminately arrang bres falling upon 'the conveyor is carm 'fied around with the conveyor by 'the friction between the inner fibres and the outer surfaces of the conveyor and the inter-engagement of the fibres with each other so as to form a mass 24 (Fig. 3) of fibres completely covering the conveyor, the fibres forming the mass being completely interentangled and intermingled with each other.

In other words, the conveyor functions to form a hollow mass of indiscriminately arranged fibres which completely surrounds the conductor Il), but out of contact with it, and which rotates about the conductor. This rotating mass of bers is continually advanced forwardly toward the apex of the cone I8 where the fibres contact the conductor I 0 and where they become attached to the conductor. The mass of iibres is advanced to the -apex end, that is to the application zone, both by the conical formation given the conveyor and by the adherence of the iibres to the conductor.

It will be understood that while the fibres are being continually advanced to the application zone additional fibres are being continually supplied to the revolving mass from the carding apparatus, the mass building up in thickness from the end of the cone I8 where the conductor enters it to the exit end of the conc where the bres are applied to the conductor, as shown in Fig. 3 of the drawing.

The conical conveyor I 8, as shown, is provided on its surface with an upraised wall 25 defining a thread from one end to the other of the conveyor and arranged so that when the conveyor is rotating it will engage the innermost fibres of the mass of fibres 24 to assist in moving the mass forwardly to the application zone, and moreover, to effect a more positive drive between the conveyor and the mass of fibres to revolve the mass about the conductor.

I have provided an auxiliary device to assist the conveyor I8 to rotate the fibrous mass and to advance it to the application zone. This consists in a cylinder 26 mounted below the conveyor for rotary motion in bearings 21. 'I'he cylinder 26 is mounted to rotate on an axis parallel with the axis of rotation of the conveyor, and is arranged with its surface relatively close to the surface of thefconveyor, and substantially coextensive with it. Arranged on the surface of the cylinder 26 is a thread 28 arranged to engage the outermost fibres of the revolving mass 24 so as to advance the fibres to the application zone. 'I'he cylinder 28 further functions to assist the conveyor to revolve the mass of fibres about the conductor, and also to support the lower portions of this mass, as shown in Fig. 3. The cylinder 26 is provided with a driving pulley 29 over which a driving belt 30 is passed. This belt, as shown is driven by a pulley 3l mounted to rotatey with the doffer drum I6. The cylinder 26 is driven in a counterclockwise direction, as shown in Fig. 2, and in the particular form of the invention shown is driven at about 52 R. P. M.

Cooperating with the conveyor I8 is a rotary whirler 32 which engages the iibres applied to the application zone of the conductor so as to revolve or twist them about the conductor and to condense them upon the conductor. This whirler is located at the exit end ofthe application zone and comprises a rotary member 33 (Fig. 4) having a conical shaped passageway 33a therethrough which decreases in diameter from the entering to the leaving end. the leaving end determines the diameter or size of the covered conductor leaving the whirler.

The diameter of The whirler may be and as shown in Figl 4 is provided with a. removable part 34 in which the portion of the passageway 33a of smallest diameter is formed, and which may be removed and replaced with another of the same or different Adiameter to compensate for wear, and also to vary the 'exterior diameter of the covered conductor. The whirler may also be provided at its smaller end with polishing plates 35 formed of spring material and secured at their edges to the whirler so as to have a slight yielding movement. The rotary member 33 is mounted in a ball bearing 36 whichin turn is mounted in a frame or standard 31. A pulley wheel 38 is attached to the member 33 over which a suitable driving belt (not shown) driven by any suitable means is passed to rotate the whirler.

The Whirler is rotated at a high speed, the particular speed depending somewhat upon the form of the wire. Thus, if the conductor has a rectangular cross-section, the whirler Will be driven in the form of the invention illustrated at about 1533 R. P. M., whereas if the conductor be round in cross-section the whirler will be rotated at about 3577 R. P. M. The whirler is rotated in the same direction of rotation as the conveyor I8. The exterior libres of those applied to the conductor I0, are carried around the conductor by thel whirler which imparts to the mass of fibres in the application zone a rotary motion about the conductor. That is, the fibres in the application zone, as well as those on the conveyor are revolved as a mass about lthe conductor. the speed of the mass increasing from the entering end of the conveyor i8 to the exit end of the whirler 33.

As the conductor I is held from rotation while the brous mass revolves, the libres in the application zone will be wound or twisted around the conductor as it advances. The inner fibres which have become attached to the conductor, of course, do not rotate, but will be held against rotation as they are drawn along' with the filament. These fibres in turn tend to retard the rotary motion of the fibres interengaged with them, with the result that the speed of rotation of the whirling mass of fibres is reduced from the outermost fibres to those adjacent the conductor. This action causes a continuous rearrangement of the fibres in a circular direction about the conductor.

In addition to this, the fibres which have become attached to the conductor l0 are drawn along in the direction of travel of the conductor at a greater speed than the fibres in the outer layers of the whirling mass. This causes a continuous rearrangement of the fibres longitudinal-- ly of the conductor between thc innermost fibres attached to the conductor` and moving with it, and the outermost fibres.

Thus, there is a continuous rearrangement of the fibres both in a longitudinal and in a circular direction about the conductor. These two rearrangements result in bringing the bres into substantially a completely intermingled and nonparallel, compacted and twisted relationship.

It is preferable in certain cases to cover the conductor I0 with-a suitable adhesive before it enters the conveyor I8. For the purpose of applying the adhesive to the conductor, I have provided a suitable adhesive pot or receptacle 39 between the pulley I3 and the conveyor and through which the conductor is passed and which ls coated with an adhesive as it passes through. Any suitable adhesive solution, such as shellac, synthetic resin varnishes, resin, gum solutions,

etc., may be used. After the conductorpasses through the adhesivepot 39 it passes directly to and through the conveyor I8. Suitable spray devices may be used instead of the device 39 to apply the adhesive tothe conductor, because they obviate the necessity to use wipers. Moreover, spray devices are preferable in cases of rectangular and odd shaped conductors.

My apparatusv therefore applies a fibrous coating to a conductor, the fibres in the coating from its inner to its outer surface being completely inter-entangled and interengaged so that fibres cannot become separated either laterally or longitudinally either by bending the conductor or subjecting it to rough treatment.

It will be understood that after the conductor I0 passes the application zone at the end of the conveyor IB, it may be subjected to certain other finishing operations. Thus, it may be passed through a suitable polishing device 40. The polishing device 40 comprises a pair of opposed polishing shoes 4I (Figs. 6 and '7) mounted upon a plate 42 which is rotatably mounted in a bearing 43.y The brushes are formed oi a iiexible ma terial and are arranged when the conductor i8 is passed between them, as shown in Figs. 6 and 7, to apply apressure to its coating and thereby polish the coating as the shoes revolve. The plate 42 has a pulley 44 attached thereto over which a suitable driving belt (not shown) is passed.

After the covering has been applied to the conductor ii), it is often desirable to impregnato the fibres with a suitable electrically insulating varnish, such as lacquer. For this purpose, the conductor is advanced through a suitable bath 45 of the insulating varnish where the fibres are inipregnated.

From the receptacle 45, the covered conductor I0 is directed through a finishing whirler 46 which comprises a flexible shoe 41 (Fig. 5) arranged to bear upon the covering of the conductor as it passes through the whirler so as to polish the covering. The shoe is mounted upon a rotary member 48 to which a driving pulley 49 is attached.

The conductor may then be passed through a drying oven lll,y which serves to dry the insulating varnish, and from the oven the conductor may be passed through a suitable device 5i for applying a coating'of wax or talcif such coatings are desired.

It is to be understood that the conveyor I8 need not be of conical formation, but may have other forms. Thus, it may be cylindrical. The conveyor may also consist essentially in a plurality of pin-like members 52 (Fig. 8) projecting laterally from a supporting journal 53 and arranged so that when the journal is fitted into the machine, as is the conveyor I8 in Fig. 1, the pins will be directed in the direction of travel of the filament. The pins preferably will be tapered toward each other in this direction, as shown. The fibres which are fed to these pins from the carding apparatus are caused by the pins to assume a cylindrical formation about the conduc tor, and are advanced longitudinally 'of lthe pins to the application Zone. Also, as shown in Fig. 9, the conveyor may consist of a screw 54 that is arranged to rotate on an axis substantially coincident with the conductor as it passes through the machine. This screw receives a mass of fibres from the carding machine, forms them into `a whirling mass about the filament and positively pitch of this screw may be evcn or it may vary, as desired. f

It will'be understood that my process and apparatus may be used to apply various fibres, such. as cotton, jute, wool, etc., to filaments of various characters. The filaments cove'red may be solid or hollow, may be of round, square, cr rectangular cross-section, or may consist of strands of relatively small or relatively large diameters twisted together. In each of these cases, the conveyor functions to form a hollow mass of rotating fibres, advance the fibres to an application Zone where the fibres are twisted about the conductor by the combined action of the conveyor and the associated whirler and are condensed on the conductor by the whirler.

It is to be understood that the brous material may be applied directly to the filament, cr may be applied in combination with various other materials. For example, the fibres may be applied to a coating of rubber which has previously been applied to the filament.

Furthermore, my process and apparatus may be used to apply heat-insulating material to pipes, etc.

While I have shown particular embodiments of my invention, it will be understood of course that I do not wish to be limited thereto since many modifications may be made, and I therefore contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of this invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:-

l. Apparatus for applying fibrous material te a filament and like member comprising means for continuously advancing said filament in a longitudinal direction, a cylindrical member surrounding said lament arranged to rotate about said filament, means for rotating said cylindrical member, and means for continuously dropping fibres a sufficient distance to insure a haphazard arrangement between them and onto the outer surface of said cylindrical member, to build up on said surface a mass of intertangled fibres increasing in volume progressively substantially from the end of said cylinder where said filament enters it to the other end where said filament leaves it, said cylindrical member arranged by its rotary motion to rotate said mass of fibres around said filament and means acting on said fibres to advance them forwardly on said cylindrical member to its end where said filament leaves it to apply said fibres to said filament.

2. Apparatus for applying fibrous material to a filament and like member comprising means for continuously advancing said filament in a longitudinal direction, means for applying an adhesive to said filament, a cylindrical member surrounding said filament and arranged to rotate about said filament as an axis, means for rotating said cylindrical member, means for continuously delivering loosely associated non-parallel fibres to-the surface of said cylindrical member, and a. thread on said surface of said cylindrical member arranged toerigage said fibres so as tc advance them longitudinally of said cylindrical member in the direction of travel of said filament to the end of said cylindrical member where they are applied to said filament.

3. Apparatus for applying fibrous material to a filament and like member comprising means for continuously advancing said filament in a longitudinal direction, a conical member surrounding said filament and arranged to rotatev on its axis,

the apex of said conical member being directed in the direction of motion of said filament, means for effecting relative rotary motion between said conical member and said filament, means for continuously delivering loosely associated fibres to the surface of said conical member, the conical member advancing said fibres to its apex where said fibres are applied to said conductor, and an auxiliary rotary device adjacent said conical member acting on said fibres after they have been delivered to said conical member to assist said conical member to advance said fibres toward said apex.

4. Apparatus for applying fibrous material to a lament and like member comprising means for continuously advancing said filament in a longitudinal direction, means for applying an adhesive to said filament, a cylindrical member surrounding said filament and arranged to rotate about said filament as an axis, means for rotating said cylindrical member, means for continuously delivering loosely associated non-parallel fibres to the surface of said cylindrical member, a second cylindrical member substantially coextensive with said first cylindrical member arranged to rotate on an axis substantially parallel with the axis of rotation of said first cylindrical member', and having itssurface relatively close to the surface of said first member, means on the surface of said second cylindrical member engaging said fibres so as to impart a rotary motion thereto in the same direction as the motion imparted to said fibres by said first cylindrical member and to advance said fibres on said cylindrical member in the direction of travel of said filament so as carry said fibres to the end of said first cylindrical member where they'are applied to said filament, and means for rotating said second cylindrical member.

5. Apparatus for applying fibrous material to a filament and like member comprising means for continuously advancing said filament in a longitudinal direction, means for applying an adhesive to said filament, a cylindrical member surrounding said filament and arranged to rotate about said filament as an axis, means for rotating said cylindrical member, means for continuously delivering loosely associated non-parallel fibres to the surface of said cylindrical member where they collect in a. loosely associated mass on the surface of said member and are drawn from it atits forward end in the direction of movement of said filament by the adhesive on said filament, a second cylindrical member below said first cylindrical member substantially coextensive with it and arranged to rotate on an axis substantially parallel with the axis of rotation of said first cylindrical member, and having its surface relatively close to the surface of said first member so as to engage and support said mass of fibres that hang below said first cylindrical member, and means for rotating said second cylindrical member in a direction to impart to said fibres on said first cylindrical member a rotary motion in the same direction as that imparted to them by said first cylindrical member.

6. Apparatus for applying asbestos fibres and the like to an electrical conductor comprising means for advancing said conductor continuously in a longitudinal direction, a cylindrical member surrounding said conductor arranged to rotate about said conductor as an axis, means for con-- tinuously delivering a loosely associated mass of non-parallel asbestos fibres to the surface of said cylindrical member, feeding means on said surlongitudinal direction, means for continuously dropping bres toward said filament a sufficient dlstance to 1nsure a loose haphazard arrangement whirler adjacent said end of said elongated mernber to establish between said elongated member and the Whirler an application zone on said iilament in which said fibres are applied to the iilament from the elongated dense and compact the libres in said application zone onto said filament.

i5. Apparatus for to rotate said fibres and to advance them forwardly to the apex of the conical member where Patent No. 2,151,598. A

CARL R. It :iel'iez'eby certified error read whether; pg@ 1.,

.CERTIFICATE on CORRECTION.

OBERHAIER.

appears in the printed. specificationv of the yabove numbered patentv requiring correction as follows: column, line 55, 'after the word "apparatus" :insert a period and for second column, line 55, and that the said Letters Patent chou that the same may -conform tothe record plied to the filament to condense, and compact the ibres on the filament when the whirler is rotated in the same direction of rotation as said conical member, and means for rotating said Whirler in the same direction of rotation as said conical member.

16. Apparatus for applying ilbrous material to a lament and rounding sai-d lila-ment arranged to rotate about it, means for rotating said conical member,

conical member, said conical member arranged by its rotary motion to rotate said fibres and to advance them forwardly to' the apex of the conical member where they leave the member, a whirler adjacent the apex of said conical member to establish between said apex and said whirler an application zone on said lament in which 'said fibres are applied to the filament from the conical member, and means for rotating said Whirler inthe same direction of rotation as said conical member and at a relatively higher speed so as to twist, condense and compact the libres in said application zone onto said filament.

CARL F. OBERMAER.

September 2'?, 1958.'

Page l, second Claim Li, after "as" insert tog' lclbe read with this correction therein ofthecase in the Patent Office..

Signed and sealed this 6th day of'December, A., D. 1958.

(Seal) Henry Van Arsdale Acting Commissioner of Patents.

"whether" 

